Recently renamed Molecular and Cellular Bioenergetics, this Gordon Conference was last held in June, 2001, with the next meeting to be held June 22-27, 2003 at the Kimball Union Academy in Meriden, NH. The traditional focus of this meeting is on the mechanisms of oxidative phosphorylation and electron transport, and these continue to be central themes in the next conference. Aided by high resolution structural data on the F1F0 ATP synthase complex and by the application of novel dynamic measurements of rotary motion, important insights are emerging into the mechanism of proton-coupled ATP synthesis. Similarly, with the appearance of new high resolution structures of respiratory chain complexes, insights into the molecular mechanisms involved in electron transport, proton movement and the coupling between these two processes are also emerging. Moreover, this Conference has expanded to become a major platform for the discussion of mechanistic information obtained on integral membrane transport proteins using X-ray crystallography, spectroscopic techniques and molecular biological approaches. Recently discussed systems include bacteriorhodopsin, halorhodopsin and aquaporin, while the high resolution structure of the ABC transporters will be featured at the 2003 Conference. In addition, this meeting has also expanded into cellular bioenergetics and disease, with presentations in 2003 on the function and regulation of V-ATPases, the mechanism of assembly and targeting of bioenergetic complexes and the molecular basis of defects in copper absorption and resistance to intracellular parasites. The proposed meeting should thus accomplish the goal of presenting the cutting-edge research in the area of molecular and cellular bioenergetics. The participants at the Bioenergetics Gordon Conference include the leaders in this field, drawn from academics, government and industry, as well as more junior scientists, including many graduate students and Postdoctoral fellows, who represent the future of this area. A major use of the support sought in the current application is to assist such junior people in participating in this meeting. The Gordon Conference is organized to maximize the opportunity for discussion and for the presentation of the latest findings in this area, with poster sessions occurring every afternoon, discussion periods after each formal session and one entire morning devoted to workshops focused on short presentations by poster presenters.